* fix(cli): make --no-warnings, the exit code and -f github work
PIIProblem never got the `level` attribute that show_problems() reads for
--no-warnings, so the flag crashed with AttributeError as soon as a file
had a finding. Findings now have level "error" (score 1.0) or "warning",
the same split the colored output already used.
show_problems() always returned 0 and run() overwrote its result for every
file, so the CLI exited with 0 even when it reported PII. show_problems()
now returns the number of findings it printed and run() adds them up, so
the exit code is 1 when any finding is reported.
-f github printed `::<score> file=...`, which is not a workflow command, so
GitHub Actions never created annotations. It now prints ::warning and
::error commands with escaped property values and message, and drops the
./ prefix that `presidio .` adds to file paths.
The problems test fixture used Mock objects, which create any attribute on
access and so hid the missing `level`; it now builds real PIIProblem
objects.
* fix(cli): validate the threshold read from the config file
PresidioCLIConfig.parse() range-checked the current threshold (the default
0) instead of the configured value, and only converted the configured
value afterwards. `threshold: 5` was accepted and filtered out every
finding, and `threshold: abc` raised an uncaught ValueError. The
configured value is now converted and range-checked before it is stored,
and invalid values raise PresidioCLIConfigError. This also covers YAML
booleans such as `true`, which float() would accept as 1.0, and integers
too large for a float.
